de stubner



E. DE STUBNER. METHOD OF MAKING MOLDS AND APPARATUS TIIHREFOR.

Patented Oct. 3, 1922..

APPLICATION FILED JAN.2I. 1920- IIENEWED APR-18,192].

l atented met. 3?, i933.

EMILE srunivnn, or new vonrr, n. tr,

manurnorunme- GOMPA.1\TY,OF name BET, GONNEGTICUT, A CGRIORATIUN 01? METHOD OF MAKING- MOLDfi AND APPARATUS THEBEFOR Application filed Ianua1'y2l, 1920, Serial No. 353,127. Renewed April 18, 1921. Serial No. 462,340.

To all whom it may concern:

Be it known that l, Earns: on S'r'onnnn, a

citicen of the ltepublic of Switeerlaud, resid ing New York. in the county oi. New Yorlr and iiltate at New Yorl have invented certain new and useiul provenients 1n Methods of Malring lilolds and Apparatus Therefor, O'f which the following is a full, clear, and enact description.

The invention which constitutes the sub-- ject-matter oi this application relates broadly to the art of obtaining molds or casts of engravings insteel, copper or other material, of heliogravures, electrotypes, etc, tor use in galvanoplastic processes.

It is an object of the invention to provide a method which will insure tliatthe line lines oi the engraving, electrotype, orother object shall be perfectly reproduced in the mold or cast to the end that a perfect dupl1- cate ot' the original may be obtained therefrom by electio-deposition of metal thereon.

The invention consists broadly in covering the ob ect to be reproduced while in a vac uum with a layer ofnormally hard but temp porarily fluid or plastic material, allowing the material to partially harden as by cooling it the material has.beenheated, and iinally subjecting it to heavy pressure while hard.-

ening, or coolingto normal temperature.

The invention is particularly well adapted to]: use inthe making of records in the plionograpliic artand will theretore he more fully described practiced in connection therewith. Certain terms common to this artwill be usedqbut merely for convenience of description. The term wax used is intendedto mean any material whichbecomes plastic or fluid upon the application oi heat. It to be understood, therefore, that such des iription is innoi vise to he talren as limitation of the invention but merely as an illustration oi? its applicationyto one particular art. a

The invention also contemplates the pro vision ct apparatus'for the successful practice or the invention.

In the manufacture of commercialrecords as at present conducted, three electrotypes intervene between the original war: and com c mercial records. The first, called the mas.-.

tor, is derived from the original wax rec- 0rd; the second. called the mother, is derived from the master; and the third called the Stamper is derived from the mother. The first and third are true negatives of the 01' 'nal wan record, the second a positive of the same.

The master, being a negative, is, of course, adapted :Eor use a stamper in pressing or stamping commercial records which are :fao similes of the original. For various reasons, however, it is not desirable so to employ the master, the chief perhaps being that the original wax record was probably unavoidably sacrificed in making the master. Po sible injury to the master would therefore result in the permanent lossoi recorded sound waves.

Considerable time is necessarily required in obtaining the three electrotypes and this constitutes one of the great objections to the three-electrotype method of making commercial records. It he seemed impossible, however, to devise a practical method which would require less than three electrotypes, principally, it seems, because no other known method would so faithfully reproduce the reverse of the sound waves to be copied.

1 have discovered a method of making mothers which requires much less time than is required by the three-electrotype method and whichproduces mothers that are faithful copies in the reverse of the master and that lend themselves as re. l lyas the origri nal wax record to the makin of electrotypes therefrom which, in the pliono -raphic art,

":5 would he stampers for use in making the final. commercial records. The method consists in n'ialring war. mothore from the master and using them in the making of stampcrs. The mothers are made h coverinc' thectace of the master with 'ssrenon are constants s-sarrrovnonn till the originally l a hill tweenthe wax and master efliectually pre-.

cate of the original wax record free from imperfections such as blow holes due to confined airor todrawing and which may be subjectedto any operations to which the original waxrecord maybe subjected as, for example, the making'ofelectrotypes.

In order thatthe method may be morereadily understood, it willbe more fully describedin, connection with the apparatus shown in the accompanying drawing in Fig. 1 shows schematic View of the apparatus as arranged for battery operation, only one complete f apparatus, however, being poured.

shown V Fig. 2 illustrates the order of making the various records,O being the original wax,

A 'themaster, B the mother, C" the Stamper, and R the commercial record;

. Fig. 3 is asection showing the waxcovered master in place in the bowl of the vacuum pan- I 7 1 Numeral 10 indicates a tank containing a supplyof'waxkept in a molten condition pre erably'b'y meansof an oil bath in a container 11, a suitable source of heat being supplied asby a series of gas burners 12 {numeral 13 indicating an exhaust pump. Letter V indicates a vacuum an comprising a bowl let-anda top or cover' 5. Located-above the same is a receptacle 16 adapted to hold sulii'cie'nt'wax to make'one mother. If desired, a 'meansf17for visualizing the temperature' and quantity of the wax in the recep't'acle and a supplemental heating means 40.

18 for the samemay be provided. Suitable conduits 19, 20, 21 are provided between the wax tank and receptacle, the latter and the vacuum pan, the latter and the exhaust vpump, respectivel ,the conduits being provided with suitab e cut-oflt's 22, 23, 24. The conduit 21 preferably includes an exhaust chamber 25 to facilitatethe quick exhaustion of the vacuum pan. Unions 26, 27 in the conduits 20, 21 permitthe pan to be severed therefrom for anypurpose a'sfor setting it aside for cooling after the wax has been The bowl is supported on'a hot plate 28 "which serves to heat thebowl'and master in place within the same, prior to the pouring "of the wax, for preventing undesirable sudden chilling' of the latt'er.

The 'master is usually provided with a central hole and inthis is pl'acedla suitable pin or post 29. The post is preferably threaded, adj acentits tip 30 that enters the 7 master, to receive a small" disk 31 which lies flat on theimasterand' which will be embedded in the wax-mother, the post and disk subsequently serving '51s a center contact in the electrolytic process of making a stamper. The upper end of the post may be provided with a cap, preferably removable, to facilitate the lifting of master and mother from the bowl.

After the wax on the master has cooled to a gummy-like consistency, which will be in about fifteen minutes, a metal slab of substantially the same area as the top of the mother is placed on the latter for supporting heavy wei hts or other pressure. The pressure applied should be suflicient to press the mother into such intimate contact with the face of the master that the natural tendency of the wax to draw or contract does not act in a direction parallel to the face of the master. Forty to sixty pounds per square inch has been found sufficient to accomplish this result. The pressure may, however, vary within quite wide limits depending on the wax used. The mother so produced is a perfect copy in the negative of the master and has a smooth polished surface equal to that of the master against which it was in contact.

The mode of operating the apparatus is substantially as follows :-The vacuum pan, preferably of bronze, with the master in position, is heated by the hot plate 28 and exhausted to as high a degree as possible, say 29 inches by the gauge. Molten wax is then allowed to flow from the receptacle 16 into the pan to cover the master to a depth of an inch or more after which the wax and exhaust conduits are closed by their respective cutoffs-23 and 24, the latter also opening the pan to the atmosphere. The pan may now be severed from said conduits and set aside to cool until the wax is of a gummylike consistency after which the cover is removed and the wax subjected to heavy pressure as already indicated. After the wax is completely cooled the master with superposed mother is removed from the bowl and the mother separated from the master. The

mother is then subjected to electro-deposh tion of metal, the electrotype so obtained be- 7 ing employed as a Stamper for making commercial records, a new mother being used for each stamper made, primarily for the reasonlthat the conductor on the mother is usually damaged in separating it from the electrotype.

The time required in making mothers by my method is approximately one fourth of .be subjected at one time to electro-deposition of metal for the purpose of obtaining stampers and four times as many records can be made at the end of the period required to make one electrotype as could formerly be made for the reason that four StZLIDPBIS are now available Where only one was available under the three-electrotype method.

This saving in time is'perhaps of greater importance in the phonographic art than in any other on account of the nature of the market demand for records. When first re leased to the market, the demand may often exceed the supply. My invention enables a larger initial quantity of records to beput on the market than was formerly possible in a given time or to state facts a different way, enables tl'ierecords, the product of one stamgier, to be put on the market at an earlier date due to reduction of time of manufacture made possible by the practice of my invention.

il hen there an immediate demand for a great number of records a certain number of stampers are of course required and the zulvautagcs of the method will be obvious. Should. the demand die out all of the stampers, excepting the one original may be discarded if desired as the time element involved in the production of new stampers by this method is not a factor should a sec end or third demand. arise. This avoids the care required in preserving matrices to take care of future demands, also avoids the tying up of capital in matrices and also eliminates the space, trouble and equipment for tahingcare of these matrices.

The material used for making the molds or mothers should preferably be of such character that the mold surface thereof will remain unaffected by atmospheric conditions at ordinary temperature and pressure. The so-called recording waxes have been found to give the best results and this of course is an added zulwultage. as it relates to the phonographic art.

What l claim as new and desire to sccu re by Letters Patent is:

1. The method of making a mother from a masterwhich consists in covering' the latter with molten wax in reduced atmospheric pressure, partially cooling the wax, and

then subjecting it to pressure while cooling to normal temperature.

The method of maliiing mother from a master which consists in covering the latter 'tli molten wax in reduced atmospheric press .re, cooling it until of a gumniydike consistency and then. subjecting it to pres sure while cooling to normal temperature.

The method of making); a mother from a master which consists in covering the latter with molten wax in reduced atmospheric pressure, partially cooling the wax, and then subjecting it to uniform and continued pressure while cooling to normal temperature.

4:. The method of making a mother from a master which consists in covering. the latterwith molten wax in reduced atmospheric pressure, partially cooling it to a gummy like consistency and then subjecting it to a uniform and contained pressure while cooling to normal.temperature.

The method of making a mother from a master which consists in preliminarily heating the latter and covering it with molten wax in reduced atmospheric pressure, partially cooling the wax to a gummy-like consistency, and then subjecting it to pressure while cooling to normal temperature;

6. The method of making a mother from a master which consists in covering the lat-- ter with recording wax in reduced atmospheric pressure, partially cooling the war: untilof a gummy-likeconsistency, and subjecting it to heavy pressure while cooling to normal.

'ZTlhe method of making a mother from a master which consists in covering the latter with a layer of thermoplastic n'iaterial in reduced atmospheric pressure, partially cooling the material, and then subjecting it to heavy pressure While cooling to normal temperature.

8. Themethod of obtaining a mold or cast of an object which consists in covering it with a layer of temporarily fluid material. while in a vacuum, permitting said material to partly set or harden, and then subjecting the same to heavy pressure while it permanently sets or hardens under ordinary conditions of temperature and atmospheric pressure.

9. The apparatus for making molds com.-

prising a vacuum pan, a supply tank for a thermoplastic material, a receptacle for a portion of the latter interposed between the tank and vacuum pan and connected by conduits therewith, and a vacuum pump connected to the vacuum pan for exhausting the same.

10. The step in the method of making a mother from a flat disk master which con-- sists in covering the latter with a layer of ll. l 0

moldable material in reduced atmospheric pressure.

11. The method of making a mother from a flat disk master which consists in covering the latter with a layer of moldable material in reduced atmospheric pressure, and

i the Wax in a form in reduced atmospheric permitting it to set or harden in ordinary atmospherictemperature and pressure.

14. The method of reproducing a sound record, which consists in firstmaking awax master, naklng a metal master therefron'l,

making a Wax nother from the metal mas- I ter, and then making a record stamper from pressure, and then subjecting it to pressure while hardening.

18. The method of forming a fiat wax slab or disk for use in the production of sound records, which consists in first casting the Wax in a form in reduced atmospheric pressure, and then allowing it to harden under pressure and at ordinary tempera- V ture.

19. In an apparatus for making flat wax slabs or disks for use in the production of sound records, means for casting the slabs or disks in reduced atmospheric pressure.

20. In an apparatus for making flat wax slabs or disks for use in the production of sound records, means for casting the slabs or disks in reduced atmospheric pressure, and means for removing the slabs or disks While in an unhardened state.

In testimony whereof, I aflix my signature.

EMILE on STUBNER. 

